1) Field of the Invention
This invention relates, in general, to devices for cutting vegetation, notably brush-cutters or edge-trimmers and, more specifically, the cutting elements made from synthetic material for such devices.
2) Description of Related Art
For several years, various shapes of cutting filaments or lines have been developed for use in a cutting head, driven by an electric or thermal motor, so that the rapid rotation of the head rotates the line or lines that tend to adopt a rectangular extension under the effect of centrifugal force. These lines are generally manufactured by extruding or drawing polyamides.
Whilst older lines had a circular cross-section and were entirely smooth, lines have now been developed with varied and/or evolutive transversal cross-sections, purported to reduce the operating noise of the device by acting on turbulence.
There are also lines which comprise edges, grooves, recesses or even line deformations along their length.
These known lines, although some do allow the noise to be substantially reduced whilst the device is being operated, nonetheless have one or more of the following disadvantages:                the shape of the transverse section or its evolution may, in some instances, weaken the line and make it liable to break, notably at points where this transverse section is thinner;        the specific transverse section of the line may compromise its efficient retaining in the cutting head, in particular if this section differs significantly from standard sections such as a circular or a square section;        line manufacture is made more complicated and/or more onerous;        